Bearing Decision

I have been debating how I want to deal with the bearing surfaces.  I was going to go with a thinner angle stock to line the bearing surfaces and glue them on and anchor them with screws at the ends. After lots of consideration, and a quick consult with someone much more experienced with glues and supporting other people building from plans, I have changed my mind. Thanks MIK for talking me out of it.

The thinner would be sufficient to handle the load but there are other considerations.  I am planning on this CNC being able to be built by others. Gluing aluminum is not a real easy task. It takes a lot of prep work and other people might not be as able to have the resources to do it properly. If not glued well, it will have a tendency to pop loose and it being on disparate materials with different coefficients of expansion, it will be prone to trouble if you are not careful. I am going to go ahead with 1/8 " (about 3mm) 6063 aluminum angle and attach with countersunk screws. If I go thinner with the angle, it will tend to deform around the screws. It's not that much more expensive and it is still pretty light. I can live with it. Online Metals should have it to me in a few days.

The .other things that I have been waiting on have finally arrived. I decided to go ahead and get a really nice fence for my router table. It will make preparing the stock much easier and besides, I wanted it. I picked up the 17" Incra LS. Gold and red anodized aluminum is so pretty. It is a bit extravagant but a real pleasure to use. To prepare the stock for the angle, I also picked up a new bit for my router. I bought this one from Grizzly for $20. It's a lot easier than messing around with cutting the angles on the rails for mounting the aluminum any other way

I have also made one more decision. I am going with a 2' x 4' cutting area table for this first CNC router. I don't yet have things organized to a point where I can fit a full 4' x 8' unit right now and if I went much smaller, I would be disappointed by the size limitation of anything smaller. 2' x 4' sheets are easy to come by at the lumber yards and easy to fit in the car.  It will also be big enough to make 4' wide parts for a larger machine. I can live with that.